Linux may be a free platform for many and a reasonably inexpensive alternative to Unix and proprietary platforms for others, but make no mistake. For years, Linux has been big business, and if projections made by the market researchers at IDC turn out to be correct, in a few short years the Linux server ecosystem spending on hardware, software, and services directly relating to the platform will hit $49 billion by 2011. That's more than twice the $21 billion in Linux-related server spending that IDC reckons the companies of the world accounted for in 2007.

The Linux ecosystem study was sponsored by the Linux Foundation, the non-profit consortium of hardware and software vendors and other indy Linux luminaries that was the result of the merger of Open Source Development Labs and the Free Standards Group back in early 2007. The Linux Foundation, being open, is distributing the resulting report that it commissioned, called The Role of Linux Servers and Commercial Workloads, for free, and you can read it here for yourself, if you are so inclined.

I will give you some of the high points, and throw in a few points of my own. The key point in the report, aside from financial figures and pretty charts that display them, is that Linux continues to expand beyond the Web infrastructure workloads that typified its first decade of commercial use and continues to make headway into the data centers and data closets of the world, where Unix, Windows, and proprietary platforms have ruled. Linux is making headway into database and application serving, roles where it has been available for many years. But companies are loathe to change their backend systems and often wait until they have a compelling economic reason to change their systems to also change their underlying platforms. In the early years, Linux was part of the buildout of Internet-style networks, and this was a greenfield installation for all but the most sophisticated telecommunications, service provider, and university organizations, where Unix was the name of the game for a long time.

IDC says that Linux-based application software is nonetheless taking off. In 2007, Linux platforms accounted for about $10 billion in application software spending, a mere 4 percent of the $242 billion in licensing of application software. But by 2011, IDC believes that Linux platforms will have a 9 percent share of an application software market that will grow to $330 billion, or about $31 billion in sales. Over that four year span, Linux app sales will more than triple while the market will only expand by 36.4 percent. The Linux application space is therefore growing at nearly six times the rate of the expansion of the application software market itself. This is akin to the early years of Linux server sales back in the X86 server days during the dot-com boom and in the wake of the dot-com bust, when everyone was looking to do things in a less expensive manner inside the data center.

In a sense, the dot-com bust is still going on, and companies are still trying to wean off Unix and proprietary systems when they can. "The growth of Linux as a platform for business-oriented workloads appears to be coming largely from migration of existing Unix deployments in combination with organic growth of Linux deployments in these same workload areas," the authors of the IDC report--Al Gillen, Elaina Stergiades, and Brett Waldman--say in explaining the growth of Linux beyond the infrastructure area.

Of course, Microsoft has spent a decade attacking Unix platforms with its ever-improving (well, sort of) Windows platforms. The Windows target that Linux vendors and application vendors have to shoot for its quite large, with Windows server platforms (plus Windows XP and Windows Vista client apps) driving $127 billion in sales in 2007, more than half of all application software spending. By 2011, IDC is projecting that Windows application sales will account for an even larger slice of the application pie--58 percent compared to 53 percent in 2007, to be precise--and that works out to $190 billion in Windows-related app software sales.

One of the wild cards in these numbers is, of course, what happens to the Solaris Unix variant from Sun Microsystems. While Sun has distributed more than 12 million licenses of Solaris 10 since launching it three years ago, it is hard to say how many are being used in production. Sun doesn't seem to have been hurt by the open sourcing--Solaris is still driving more than $1 billion in software and services sales, as best I can figure, about the same level it did as a closed source platform with fee-based licensing and tech support. Solaris shops could--and probably will--give a lot more thought to a jump to Linux now.

The other wild card is the economy. Phase changes for server platforms are sometimes driven by a new technology--such as the family of Internet protocols on Ethernet that replaced a collection of proprietary networking software stacks and peripherals to support them--but are often driven by economic downturns. The proprietary midrange shift in the 1980s was during a recession, as was the move to Unix platforms in the early 1990s. Linux got a lot of attention in the late 1990s, during the dot-com boom, but it got a lot more traction in the post-boom time of 2000 through 2004. The platform that offers the best and most scalable server virtualization for the lowest price is going to eat a lot of share if a recession happens.

One last thought. None of this includes the cost of people to manage server platforms, and the architectural design of Unix and Linux platforms gives it an edge in the data center that is equal to the massive application portfolio and vast installed base that Windows enjoys. When people are expensive and need to be removed from the equation, it is safe to bet that Linux can provide a competitive edge to Windows in terms of the ease of support. Not because of the systems that Novell and Red Hat have built to compete with Windows Update, but simply because their architecture requires fewer patches to begin with.

Why File-based System Backup is your Best Bet
File-based, Full System Backups Create Advantages Over Image-based Backups

File-based backups used for system recovery have been around for years. And, until recently, file-based meant a long, painstaking, manual process capable of turning off even the most meticulous system administrator. Image-based backups, then, seemed to solve this problem by eliminating the need to deal with recreating partitions, filesystems, volume groups or other details related to the system's storage configuration. In an image-based restore, the storage configuration and data from the original system are restored as a whole to the new system. While this method produced fast recovery times, Linux administrators began to realize disk image backup was more of an alternative method with its own set of problems and limitations than an answer to the challenges of manual, file-based backup.

Limitations to Disk Image Backup
Since disk image backups make no distinction between files and instead backup the hard drive as a group of sectors, bare-metal recovery can be quick and easy by simply rewriting a duplicate image onto a new, identical disk drive. A fine solution, as long as the old system and new system are indeed identical in types, sizes, locations- basically the exact same hardware. Any differences in hardware, however, could render an image backup unusable.

Many system administrators know first-hand the frustration caused by the inflexibility of image-based backup. "What I hear time and time again from clients is that they switched from image-based backup to file-based because of the limitations they encountered when trying to restore a backup onto different hardware." said Manuel Altamirano, Storix Software Director of Sales and Marketing. "Administrators assume they will have access to identical hardware after a disaster or for migration when the time comes. Unfortunately, so often this is not the case. Companies are left with unplanned, excessive downtime."

Even more advanced disk image backup products, that offer alterations to disk partition tables, still fail to understand more advanced and increasingly common storage configuration tools such as the Logical Volume Manager (LVM) or Software RAID (meta-disks) that also must be altered to match new hard disk configuration before data can be restored. In these cases, users must manually alter and build the configuration, usually through command-line utilities and manual editing of configuration files. This also requires users to have knowledge on how to make a system bootable. Rebuilding a system using a disk image backup requires experienced Linux administrators and could take days, weeks or longer resulting in crippling downtime for an organization.

Advances in File-based Backup
File-based backup tools today can automate the process of recording every aspect of a system separately such as disk, filesystem and boot loader configuration while supporting all popular Linux storage configuration tools (i.e. LVM and Software RAID). This detailed backup information is used to greatly simplify the recovery of a failed system from scratch, even if hardware differences are detected on the new system. Furthermore, systems rebuilt from the ground up using file-based backups often times operate better than the original because there is virtually no fragmentation when the restore is completed.

Flexible recovery based on file-based backup
File-based backup products have the ability to reconfigure disks, partitions, filesystems and other storage solutions to fit onto new hardware. This ability to adapt a backup to fit new hardware or alter the system's storage configuration is called "Adaptable System Recovery" or ASR. Only backup solutions that gather details about the original system have enough information and flexibility to make the ASR process of altering configuration so simple even novice Linux administrators can quickly perform the recovery. Once new configuration is completed, data files from the backup are easily restored onto the new hardware. Finally, the system is made bootable based on the new hardware.

The revolutionary adaptability of ASR found in file-based backup tools creates further added value for system administrators because these products can now be used for far more than just reactive tasks such as disaster recovery.

Applications for ASR:
Reactive

Disaster Recovery- restore systems in minutes after a crash, even if hardware is not the same as the original

Proactive

Provisioning/cloning- a single backup "golden image" can be used to provision different systems, even if disks, adapters or other elements are not the same.

Storage software migration- change configuration on the same system for improved performance and availability

Hardware migration- install the same system onto newer or virtual systems

New system backup management features
Products using file-based system backup have not neglected to consider a system administrator's daily backup responsibilities. These products now incorporate functionality for backup management as well as some of the most advanced features seen in backup and recovery solutions for Linux and AIX. Some advanced features designed to simplify daily backup management for system administrators include:

Graphical, Web and Command line interfaces

Local and remote backups to disk or tape devices

Sequential and random tape autoloader support

Support for SAN storage solutions

Tivoli Storage Manager integration

Oracle database backup support

Backup data encryption

Multiple compression levels

File-based Backup Solutions Provide Most Bang for the Buck
Inexpensive products exist that combine both file-based backup management and ASR in one program. Look for a file-based system backup product with advanced features like those mentioned above. In turn, regular backup responsibilities such as automatically verifying backups and encrypting backup data will become much easier. Additionally, combined ASR capabilities greatly reduce downtime and required expertise for both reactive (even bare metal) and proactive recovery projects. File-based system backup and recovery solutions are an economical and more comprehensive option than their image-based counterparts.

About the Author
Anne Stobaugh is an independent contractor working with Storix Software to educate Linux and AIX users on the advantages of file-based backup and recovery solutions.www.storix.comwww.stobaughmarketing.com